Maryland Geological Survey 339 



maxima and P. constricta. Dr. Grabau refers it to P. maxima (?). 

 Observing that " the sulcus is a trifle stronger than usual in this species 

 and more like that of P. constricta." The species is characterized by its 

 size, very gibbous form, abruptly contracted posterior end and rather 

 obscure concentric striae. 



Length, 24 mm.; height, 15 mm. 



Occurrence. — Romney Fokmatign, Hamilton Member. Evitts 

 Creek below Wolfe Mill. 



Collection. — Maryland Geological Survey. 



Palaeonetlo fbcunda Hall 

 Plate XXVI, Figs. 18-21 



Palaeonetlo fecunda Hall, 1870, Prelim. Notice Lamellibranchiata 2, p. 8. 

 Palaeoneilo fecunda Hall, 1885, Pal. N. Y., vol. v, pt. i, Lamellibranchiata ii, 



p. 336, pi. xlix, figs. 13, 15-24. 

 Palaeoneilo fecunda Keyes, 1891, Johns Hopkins Univ. Giro., vol. xi, p. 29. 

 Palaeoneilo fecunda Clarke, 1903, N. Y. State Mus., Bull. 65, p. 476. 

 Palaeoneilo fecunda Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 399, figs. 510k, 1. 



Description. — " Shell large, elongate-ovate ; length nearly twice the 

 height; basal margin broadly curving; posterior end obtusely rounded or 

 doubly truncate; anterior end regularly rounded; cardinal line arcuate. 

 Valves regularly convex below, gibbous above and in the umbonal region; 

 beaks at less than the anterior third from the end, moderately elevated 

 above the hinge-line; umbonal slope flattened, giving a slight angularity 

 to the shell above and below it, and an oblique truncation to the posterior 

 extremity. Test thick, marked in the anterior portion by fine, regular 

 concentric striae, some of which become elevated into sharp, lamelliform 

 striae, with finer intermediate ones on the posterior half of the shell." 

 Hall, 1885. 



A left valve of this species was found on the Williams Road one-fourth 

 mile east of the Queen City Hotel and Hall figured several specimens from 

 the Hamilton group, near Cumberland, Md. (Pal. N. Y., vol. v, pt. i, 

 Lamellibranchiata ii, pi. xlix, figs. 18-24) and also reported it from 

 Hardy County [W.] Virginia {ibid., p. 337). The specimen repre- 



